From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 56C643ECBCF; Fri, 4 Sep 2026 05:35:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788500147; cv=none; b=WZUnlT4k5f02n3m/26aQDlKZBO4OTCoU+BPO+V/g+OnNeDpvECOs9eN78Zmw7k8EGgr43qu/KSOL3U5fIo9cbeHxWNcGRCvZMg2fNLwykudpI4nrIRscq+fOhP0HzOPHBVhhlFjzFqMvi7eYA6IPn6lN+VOXW8BK3fjwCz0UlBM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788500147; c=relaxed/simple; bh=KlQpxXykfqS2VGR3rkqSUNBazVMQpvXyl2WcdY0KVeM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DpJSZVrEYah12AGDnEaFHXgvMwnwSByrqA9qoU6Vx+2MOmi/aZ/U72E3GtmE8H+3NGgU1c1l8UC6OsRZ2UkFuf6E6v3gcfO7SyT04go0q5hoC5+c1bWqyPFFNBRnD7WpkJI8kzTEYvrQzsSdZglqoHCBjNeeQZ7VBxCGwDm1184= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=V+Rf0aFP; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="V+Rf0aFP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B03861F00A3D; Fri, 4 Sep 2026 05:35:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788500146; bh=Ync8EEpME8RRaRP2ySTiDolN5RTOycxuGplB6xO0POI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=V+Rf0aFPHoGZ7VXxrtxm2b8k2+d0CA5vv/rJapC6snaFfoO9llfPMgZyiNjD9GuKJ 9J7nvXmD83EZdsq9Tun6KoHlbGcmte2aKoYYx3xd9ixbvpTz17aTmdMSqHCLIP0nyn T2TqWrteDKZ2s0rw8Ju7NwRZTT1szezzg6Lb3u14= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kaixuan Li , Maoyi Xie , Frank Li , Alexandre Belloni Subject: [PATCH 7.2 666/713] i3c: master: svc: bound IBI payload to the requested max_payload_len Date: Fri, 4 Sep 2026 07:00:34 +0200 Message-ID: <20260904045818.764845065@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045803.810145556@linuxfoundation.org> References: <20260904045803.810145556@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maoyi Xie commit e2bda39d7f9f285ec803e200b5c1f17143d0b483 upstream. svc_i3c_master_handle_ibi() reads the IBI payload from the RX FIFO into the IBI slot. The loop is bounded by the hardware FIFO size (SVC_I3C_FIFO_SIZE), not by the slot size. slot->data points into the IBI pool, which i3c_generic_ibi_alloc_pool() sizes at max_payload_len per slot. svc_i3c_master_request_ibi() only rejects a max_payload_len larger than SVC_I3C_FIFO_SIZE, so a driver can request a smaller one. mctp-i3c requests 1. Each readsb() then copies the controller RXCOUNT bytes (up to 31) with no check against the slot size. A device that sends more bytes than the slot holds writes past slot->data, an out-of-bounds write into the IBI pool. Bound the loop by dev->ibi->max_payload_len and clamp each read to the space left in the slot, the same way dw-i3c does. A device can still send more than the requested payload. Flush the leftover bytes from the RX FIFO so they do not leak into the next transfer. Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver") Cc: stable@vger.kernel.org Co-developed-by: Kaixuan Li Signed-off-by: Kaixuan Li Signed-off-by: Maoyi Xie Reviewed-by: Frank Li Link: https://patch.msgid.link/178227747353.2931373.15868718612134648277@maoyixie.com Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/i3c/master/svc-i3c-master.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/i3c/master/svc-i3c-master.c +++ b/drivers/i3c/master/svc-i3c-master.c @@ -455,14 +455,22 @@ static int svc_i3c_master_handle_ibi(str buf = slot->data; while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS)) && - slot->len < SVC_I3C_FIFO_SIZE) { + slot->len < dev->ibi->max_payload_len) { mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL); count = SVC_I3C_MDATACTRL_RXCOUNT(mdatactrl); + count = min(count, dev->ibi->max_payload_len - slot->len); readsb(master->regs + SVC_I3C_MRDATAB, buf, count); slot->len += count; buf += count; } + /* + * The device may have sent more than the requested payload. Drop the + * extra bytes so they do not leak into the next transfer. + */ + if (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS))) + writel(SVC_I3C_MDATACTRL_FLUSHRB, master->regs + SVC_I3C_MDATACTRL); + master->ibi.tbq_slot = slot; return 0;